英语语法分析

In May, tribal police arrested nine Tohono o 'odham members after a five-month investigation during which undercover agents purchased 250 grams of cocaine.

五月份，部落警察在长达五个月的调查后，逮捕了九名Tohono o ' odham的成员，便衣的缉毒人员从他们那买了250克的可卡因。